LIMIT GAUGES
*A limit gauge is not measuring gauge. They are just used as inspecting gauges. The limit gauges are used in inspection by methods of attributes.
*It gives the information about the products which may be either within the prescribed limit (or) not.
*Limit gauges are mainly used for checking for cylindrical holes of identical components with a large numbers in mass production.
Types
1. Plug Gauges
2. Ring Gauges
3. Snap Gauges
1. PLUG GAUGE
*The ends are hardened and accurately finished by grinding. One end is the GO end and other end is NOGO end.
*The GO end with be equal to the lower limit size of the hole and the NOGO end will be equal to the upper limit size of the hole.
2. RING GAUGE
*Ring gauges are mainly used for checking the diameter of shafts having a central hole. The hole is accurately finished by grinding and lapping after hardening process.
*We have to make two ring gauges separately to check the shaft such as GO ring gauge and NOGO ring gauge.
3. SNAP GAUGE
*A snap gauge is a form of go/no go gauge. It is a limit gauge with permanently (or) temporarily fixed measurement apertures (gaps) which is used to quickly verify whether an outside dimension of a part matches a preset dimension or falls within predefined tolerances.